Pay television employing interfering sound signal



. Aug; 15, 1967 T. A. BANNING, JR 3,335,439

v -PMr TELEVISION EMPLOYING INTERFERING SOUND SIGNAL originanl FiledJuly 1e, 1956 5 Sheets-sheet a acfmput /7 n wh and Redman im Mmm; peaerSpeaker:

f- Cu 11'-, zada omascmnin ,Jr.

Aug. 15, 41967 T. A. BANNING, JR 3,335,439,

l PAY TELEVISION EMPLOYING INTERFERING SOUND SIGNAL .original Filed July1e, 195e 5 seets-sneet s @61; 73 acfmput I [evconnedrng DMA ab e.

RBGR

RBGRBTGL RBGR RBGRB RBQRBG Q R i R B 115' 53% BQRD ask

mmf W speaker. 035

\ GVB-Rl v B i Aug. 15, 1967 T. A. BANNING, JR 3,336,439

PAY TELEVISION EMPLOYING INTERFERING SOUND SIGNAL Original Filed July16, 1956 5 Sheets-Sheet f1 original Siri p Trove.

mg mslm o Qandgg gimen. 94o

8B Mcvophone.

` Bound ehevlsion Receiving STC.

o I x05o 95 iugmfw Amp. OOO 0 5pecm\6\ nai 4. PBI

Contra. El Sync. OO\3.820 Fi;

O OO ThomcesA.Bunnmg,Jr. OOO

I l -Ooo Hmmm: i I

Aug; 1 5, 196.7 v T. A. BANNING, 1R

PAY TELEVISION EMPLOYING INTERFERING SOUND SIGNAL 5 Sheets-Sheet 5original Filed July 11e, 1955 O O O O O O O O O O Microphone.

United States Patent vided and this application July 16, 1963, Ser. No.295,484

Claims. (Cl. 178-5.6)

This application is a division of my co-pending application for LettersPatent of the United States, Ser. No. 245,- 277, tiled Dec. 17, 1962(now Patent No. 3,222,452) as a division of my earlier application,Serial No. 597,950, filed July 16, 1956, and issued `as Letters PatentNo. 3,070,652 on December 25, 1962, each of such applications beingtitled Improvements in Radio and Television Program Selecting, and Timeof Use Recording. Said application, Ser. No. 597,950 was co-pending withmy earlier application, Ser. No. 235,854, filed July 9, 1951, and issuedas Letters Patent No. 2,755,334, on July 17, 1956.

This invention relates to improvements in radio and televisionoperation, and the like. More particularly, the improvements hereinafterillustrated and described concern themselves with television and audioreception, and the means to produce such reception, whereby certainprograms being emitted from the sending station may be received byconventional operations of translation of the received signals underconditions which will produce both picture translation and audiotranslation of the picture and audio components of the program as fullyintelligible translations under acceptable excellence; or underconditions which will produce one of the above two defined components asa fully intelligible translation and acceptable excellence, but willeither fail to produce the other of such defined components, so thatonly the one component is intelligibly translated, or will produce thetranslation of the other of such defined components under non-acceptableconditions of translation.

Conveniently, the embodiments hereinafter disclosed are such that thepicture component is translated as a fully intelligible and acceptabletranslation, but the audio component is either blanked out or renderedun-acceptable as a translation. As an example of such un-acceptabletranslation of the audio component I may mention the introduction intothe audio component, of a signal of audio frequency, conveniently ofconstant frequency, such as a 500 c.p.s. hum signal, rendering thereception of the program highly distasteful to the observer.

Specifically, the improvements hereinafter disclosed include means toenable reception of the program emitted by the sending station eitherunder the condition that both the picture component and the audiocomponent are translated as acceptable translations of high quality whenthe program is of what may be termed ordinary quality, without the needof pre-pay or other special payment or credit operation; but under thecondition that the audio component of the program is either blanked outor made otherwise un-acceptable (as by injection of such a hum signal,into the audio reception), when the program is oi what may be termedspecial quality; with further provision for restoring the audiocomponent into the translation, or eliminating the hum signal from theaudio reception, either when pre-pay is made, or other special paymentor credit operation is producedby or for the person observing thereception of the program. Thus provision is made for either of twopicture translations, one with the acceptable audio translation, andwithout pre-pay or other special payment operation, and the otherwithout any audio reception, or, alternatively, with an unacceptableaudio reception; and further, with provision for restoring the audioreception or removing the objectionable noise element, such as the hum,by making prepay or bringing into operation the special payment orcredit operation previously referred to.

Certain of the features of invention hereinafter disclosed are alsoapplicable to emission and reception of audio programs alone, and not aspart of a television program. In such cases the ordinary audio programmay be received as an acceptable translation without pre-pay or specialpayment operation; but when a specia quality radio program is beingemitted, the translation thereof will either be blanked out or renderedun-acceptable by an interfering noise injection, such as the hum signalpreviously referred to, unless and until the pre-pay or other specialpayment operation is made or used.

In connection with the foregoing objectives, it is a further object tomake provision for producing a recording of the times when any of suchspecial programs are tuned by the observers receiver, whether suchprograms lcomprise television programs with audio reception, accordingto conventional practice, or comprise only the audio programs withouttelevision or picture translations. Such recording will enable properdistribution of payments thus pre-paid, or credit operations to bedistributed among numerous sponsors of the special programs, thus alsosimplifying auditing and related operations based on the reception ofvarious special programs, having different sponsors.

Other objects and uses of the invention will appear from a detaileddescription of the same, which consists in the features of constructionand combinations of parts hereinafter described and claimed.

In the drawings:

FIGURE 1 shows an embodiment comprising provision for both televisionsignal reception and translation, and for audio signal reception for thespeaker, together with provision for discontinuing the audio translationcompletely upon reception of a control signal therefor; together withmaking ineffective such audio discontinuance upon pre-pay or remotecontrol operation, to restore the audio component of reception;

FIGURE 2 shows an embodiment comprising provision for audio receptionand translation only, together with provision for discontinuing theaudio translation completely upon reception of a control signaltherefor; to-

gether with means making ineffective such audio discontinuance uponpre-pay or remote control operation, to restore the audio reception andtranslation;

FIGURE 3 shows an embodiment comprising provision for both colortelevision reception and translation, and for audio signal reception forthe speaker, together with provision for introducing an objectionalinterfering audio translation into the sound translation delivered tothe speaker, such interfering audio translation comprising,conveniently, a hum frequency; together with provision of means to blankout such interfering audio translation, comprising -means to produce andinject into the audio signals delivered to the speaker, an invertedaudio signal opposite to the interfering signal, by use of an inverter;and means under control of a pre-pay or remote control unit, to makesuch inverted signal effective to blank out or neutralize theinterfering signal and deliver to the speaker a true translation of theaudio signals without interference;

FIGURE 4 shows an embodiment similar to that shown in FIGURE 3, but inwhich embodiment the television translation is a monochrome translation;and

FIGURE 5 shows an embodiment similar to that shown in FIGURES 3 and 4,but without provision for any television translation, being a simpleaudio receiver with provision for producing the interfering signal undercontrol of a control signal, together with means to discontinue suchinterference upon making pre-pay or operating a remote control unit.

Each of the embodiments shown in FIGURES l, 2, 3, 4 and 5 also includesrecording means constituted to produce a time record of the receptiontuned and translated from each of a plurality of sending stations,including provision for such a recording whether the tuned reception befor a special pr-ogram or an ordinary program; and the recording in thecase of a special program will be produced only when the pre-pay orremote control operation has been made effective.

In each of FIGS. 1 and 2 of the embodiments herein disclosed provisionis made for reception of a control signal produced concurrently with theprogram signals to be translated, when the program is a special programrequiring pre-pay or some form of remote control by which a charge orcredit operation is produced against the owner or operator of thereceiving equipment. Such control signal may be produced from aconvenient location, such as the sending station from which the programis being emitted; and such control signal may be injected into the audiosignals emitted from the sending station, or otherwise, either as aradio carried signal or otherwise, provided it is produced and receivedconcurrently with the production and reception of the signals for suchspecial program. In each of the embodiments herein to be disclosed Ihave made provision for injecting such control signal into the stream ofsignals being emitted by the sending station, but I do not intend tolimit myself to such location of production of such control signal, norto its inclusion as a radio signal in the stream of signals emitted bythe sending station, except as I may do so in the claims to follow. Nosuch control Signal is needed or shown in the embodiments shown inFIGURES 3, 4 and 5.

Likewise, in each of the showings of FIGURES 1, 3 and 4 the audiosignals are produced at the sending station from which the picturesignals are emitted, according to conventional practice presently inuse; but such audio signals may, if desired, be produced and emittedelsewhere than at such picture signal sending station. Accordingly, I donot intend to limit myself to production of the audio signals at suchpicture sending station, eX- cept as I may do so in the claims tofollow.

Referring to FIGURE 1, the embodiment therein shown includes the sendingstation (so legended), which includes the schematically illustratedpicture signal producing equipment, from which the object 88 is scannedaccording to conventional practise, with both horizontal crossscans andvertical progress of such scans, producing the picture signals deliveredover the lines as shown, to the monochrome signal transmitter 94 andthence to the antenna 95, The audio signals from the microphone 132 aredelivered to and mixed with the picture signals also in accordance withconventional practise. From the oscillator 130 control signals ofselected frequency (such as 50,000 cps.) above the audible range, may bedelivered when the switch is closed, such super-sonic signals then beingmixed with the picture signals and emitted therewith, according toconventional practise.

Such control signals are produced concurrently with the sending of thepicture signals. At the receiving station both the picture signals andsuch control signals are received; and the audio signals, including suchcontrol signal, are then separated from the picture signals by theconventional sound trap 165. Thus both the audio signals and the controlsignals are delivered from such unit 166, The audio signals aredelivered over the lines 167n and 16S to the speaker 23W; but such line167 includes the switch 183 which is under control of the solenoid 184Thus energization of such solenoid opens the switch and terminatesdelivery of the audio signals to the speaker as long as such solenoidremains energized.

One terminal of such solenoid is grounded. The other connects by theline 112 to the pre-pay coin or token unit 77, whose contacts 79 and 78are normally closed. The solenoid 115 has its contacts 119 and 120included in series with the contacts of the unit 77, so that as long assuch solenoid 115 remains un-energized its contact 118 bridges suchcontacts 119 and 12011. The relay 143 ias its solenoid 144 normallyunenergized so that its contact 148 is normally lowered and does notbridge its contacts 149 and 151) Such contact 149 connects to a sourceof D C., and such contact connects by the line 151 to the contact 119 ofthe relay 115. Therefore the line 112 remains normally un-electrifiedeven though the contacts of the unit 77 and the contacts of the relay115 are normally bridged. Only when the relay 143 is energized to raiseits contact 148 will potential be supplied to the line 112; and whensuch supply to such line 112 is thus produced, it will be discontinuedif the contacts of either the unit 77 or of the relay 115 are opened.

The control signal lines 176 and 177 connect to the terminals of anoscillator 137 which includes the capacitor 147 and the inductance 138This oscillator is tuned to respond to the frequency of the controlsignal delivered over the lines 176 and 177, whereupon there will occura rise of potential on the grid 141 of the tube 140, thus permitting owof current from the plate 142 of such tube. Such plate connects by theline 146 to one side of the solenoid 144 of the relay 143, thus causingsuch relay to raise its contacts and bridge the contacts 149 and 150,with simultaneous electrification of the line 151 already referred to.Electrification of the line 151 energizes the solenoid 184, raising theswitch 183, and opening the speaker circuit. Such speaker circuit willthen remain as long as the control signal is being received and openuntil either a pre-pay is made to the unit 77 or the relay 115 isenergized by remote control. Such remote control is shown schematicallyas including the plug 83 which may be inserted into one o-f the sockets82 of the plate which is electrified.

Such remote control unit may be located at any convenient location, suchas the telephone exchange which serves the location where the receiveris located, or such as a central exchange where provision is made forkeeping records of the uses of the various receivers under itsjurisdiction.

The differential relay 153 having the solenoids 154 and 155 both actingon the common armature 156 is provided. The two solenoids of this relayare so connected and of such rnagnetomotive force producingcharacteristics, that when either of them is energized alone thearmature will be raised, but when both of them are energized at the sametime, their flux producing qualities will neutralize each other, thusterminating the holding power of the solenoid on its armature as long asboth solenoids remain energized. Such armature, when in lowered positionopen circuits the two contacts 157, one of which connects to the currentsource, and the other of which contacts connects to the line 75. Suchline 75 connects to the movable contact 67 of the station selector bywhich the needle 62 of the recorder traces a discoloration on thesensitive tape of the slowly travelling time recorder. That needle 62which corresponds to the selected station will thus be electrified, sothat the record produced on the tape will identify the particularstation whose reception was tuned at the time interval shown on thetape.

The operations of the differential relay are as follows; whenever thecontrol signal is being emitted and response thereto has occurred by theoscillator, the solenoid 154 will be energized due to the rising of therelay 143, Such energization of the relay solenoid 154n would raise thearmature 156 and thus electrify the line 75 so that the needle of therecorder, corresponding to the tuned station would thus be electrified.But such electrification of such needle should only occur when properpre-pay or remote control operation has been made. The solenoid 155 ofsuch differential relay connects to the line 112 leading to the solenoid184 of the switch 183, so that as long as such line 112n remainselectrified, such solenoid 155n is electrified, thus neutralizing theeffect of the solenoid 154, and causing the armature of the relay toremain down, or to fall in case it may have risen for an instant. Thus,until either pre-pay has been made into the unit 77n or remote controloperation has been produced, with corresponding de-electrification ofthe line 112, the differential relay will remain down, and the line 75will remain un-electried. The pre-pay or remote control operation willde-electrify the line 112, thus de-energizing the solenoid 184, andallowing the switch 183 to close, for restoration of speaker operation,and at the same time the proper needle of the recorder will beelectrified, to produce a time record of acceptance of the selectedstation program as to which the making of pre-pay or remote controloperation has been produced.

The foregoing operations respecting the speaker operation do notinterfere with continued proper reception of the picture signals, andproduction of the picture translation. Thus the observer of thetelevision screen will be able to receive a true and fully acceptablepicture translation, either with or without the accompanying audio andspeaker operation, as desired. Thus, too, since the audio component ofthe received program is a definite and highly desirable portion of thereceived program, it is evident that whenever a special program is beingemitted, the observer of the receiver in question has it within hiscontrol to either accept the picture component without the audiocomponent being a silent picture reception (non-pre-pay or non-remotecontrol), or to bring the audio component also into translation, thusproducing the desired higher quality reception, but with need of payingtherefor.

The embodiment shown in FIGURE 2 is the same as that just described,insofar as concerns for the audio translation; but in the presentembodiment the provision for the picture signals reception andtranslation and control, has not been eliminated. The showing of thisFIG- URE 2 is therefore of an audio reception and translation andcontrol, only. Also, the provisions for emission of a control signalconcurrently with the emission of the radio (audio) signals, during theoperation of the special program, and for reception of such controlsignal, and for responding to the received control signal, together withthe means to discontinue the speaker operation when such control signalis received, and for restoring speaker operation notwithstanding suchreception of the control signal, when prepay or remote control operationis produced, are the same as corresponding elements and operations shownin FIGURE l and fully described. Accordingly, detailed description ofall such elements and operations is unnecessary as respects the showingof FIGURE 2.

In FIGURES 3, 4 and 5 I have disclosed embodiments of audio signalsemission and for emission concurrently with such audio signals, aninterfering audio frequency signal, such as a uniform frequency signalto produce an unacceptable hum; and for receiving and translating suchaudio signals and such interfering audio frequency signal, when aspecial audio program is being emitted, requiring pre-pay or remotecontrol operations, so that, without special provision to neutralize ordiscard such interfering audio signal, a disagreeable and unacceptabletranslation of the special radio or other program will be produced.FIGURE 3 of such group of figures, shows an embodiment which includesprovision for emission of color picture signals, and provisions forrecepti-on and translation of such signals as a color picture raster,together with provision for receiving and translating the audio signalscomprising a portion of the program, thus producing the conventionalcolor picture and audio program, when the interfering audio frequencysignal is not being emitted. This would be the condition existing whenan ordinary program was being emitted and received in conventionalImanner. The embodiment shown in FIGURE 3 also includes provision forreceiving the interfering audio frequency signal when such signal isbeing emitted, during emission of a special program, and for includingsuch interfering audio frequency component in the translation sent toand received by the speaker, so that under such conditions of operationan unacceptable translation of the sound component is produced.Provision is then made for neutralizing or blanking out such interferingaudio signal, when pre-pay or remote control operation is produced, sothat the audio signals delivered to the speaker do not include suchinterfering audio frequency signal, and a clear, full quality audioreception is produced by the speaker.

FIGURE 4 shows an embodiment the same as that of FIGURE 3, with theexception that the emitted signals are for a monochrome picture program,and the receiver is constituted to produce a corresponding monochromeraster. The audio emission provisions, including the emission of theinterfering, audio frequency component, and for receiving andtranslating such audio frequency signals, including the interferingsignal, and provisions for neutralizing or blanking out such interferingsignals, by prepay or remote control, are the same as described inconnection with the showing of FIGURE 3. Detailed description of theshowing of FIGURE 4 is thus unnecessary.

The showing of FIGURE 5 is limited to the audio frequency producing andemitting elements, including the production and emission of theinterfering audio signal; and such showing is also limited, in thereceiver elements, to the audio receiving and translating elements,including the interfering signal, and to the inverter means, and thepre-pay or remote control means for causing the inverter to inject aninverted signal, corresponding to the interfering signal, into thesignals prior to sending them to the speaker. Thuswhen pre-pay or remotecontrol is brought into operation, during reception of a special qualityprogram, the reception will be unimpaired by the presence of the emittedinterfering signal.

'In FIGURE 3, provision is made at the sending station for injection ofthe audio frequency interfering signals (e.g., 500 c.p.s) into the audioand television signals sent to the antenna e, the switch 164e beingprovided for starting and stopping the production of such interferingsignal-s. Thus such signals may be produced only during the emission ofthe special program. At the television receiver all of the signals,including the conventional color lpicture signals, the programs audiosignals, and the interfering signal (when produced) are received by theantenna. The audio signals are transmitted from the sound trap to theunit e. At this point the lines 171e and 172e are carried to the twopole relay switch 173e having the solenoid 178e. From such switch relaythe lines 174'e and 175e are carried to the inverter unit e.Accordingly, when the switch relay is activated by energization of thesolenoid 17 8e, to close the switch contacts, the inverter is suppliedwith current of the interfering frequency. Thereupon such inverterdelivers an inverted potential and current over the lines 176e and 177e.These connect to the lines 167e and 168e leading to the speaker 169e.Accordingly, the potentials delivered over the lines 167e and 168e tothe speaker, inclu-de the audio component of the program coming 4fromthe sending station, plus the interfering frequency signal, plus theinverted version Aof such interfering frequency signal. By use of aninverter which will deliver inverted voltages opposite in phase (180degrees) to the interfering signals received over the lines 171e, 172e(which so received signals are in phase with the signals deliveredtowards the speaker, from the unit 166e), and which voltages `deliveredby the inverter unit 170e are of amplitude the same as the signalsreceived by the inverter unit, it is seen that such inverted voltagesignals will cancel out the interfering frequency signals coming fromthe unit 166e, leaving, for delivery to the speaker, only the audiofrequency signals comprising a portion of the program.

The solenoid i780 of the relay I7?,e is energized by making pre-pay orremote control operation. To this end the pre-pay coin or token unit 77ehas its contacts normally open, `and the solenoid IISe of the relay 117eis normally un-energized and in lowered contact position (it is shown inFIGURE 3 as being closed, which would produce closing of the relay 173e,as shown). The contacts of such relay 115e and the contacts of the unit77e are connected in parallel between the source of potential 1.14e andthe line lllZe which leads to the solenoid 17 3E, so that the relay 173ewill close its contacts either when the unit 77e is actuated by propercoin or token operation, or when the relay 115e is energized by remotecontrol comprising the line 84e, and the plug 33e, together with theselector board 81e.

The embodiment shown in FIGURE 4 is the same as that just described(FIGURE 3), with the exception that the showing of FIGURE 4 is for amonochrome picture production, based on monochrome picture signalsemitted from the sending station, whereas the showing of FIG- URE 3 wasfor color picture signals production, and color picture translation.Accordingly, it is deemed unnecessary to describe the embodiment ofFIGURE 4 in full detail, since the elements and operations relating tothe pro-duction and use of the interfering frequency signals duringemission of a special program, are the same as previously described.

Since the embodiment shown in FIGURE 5 is limited to the elements andoperations incident to production and reception, and translation and useof the interfering frequency signals, based on the inverter operation,with emission of special audio programs, and since the elements andoperations incident to such conditions are the same as like elements andoperations already described, it is deemed unnecessary to describe theshowings of FIGURE 5 in detail.

The term super-sonic signal or like terms, as herein used, means asignal of frequency above that frequency which is audible to humanbeings; and sub-sonic signal, or the like, as herein used means a signalof frequency below that frequency which is audible to human beings.

I claim:

1. A television and radio receiver constituted to receive and translatetelevision signals to pro-duce a first intelligible component comprisinga picture raster, and to receive and translate signals comprising asecond, intelligible component comprising sound effects related to andaccompanying said raster during the translation of said signalscorresponding to a program; and speaker means constituted to receive thesound effects component to produce the intelligible sound effectsconcurrently with the production of the raster; together with a remotecontrol station and connections between said remote control station andthe intelligible sound component delivering means, said remote controlstation and connections being constituted to cause the sound componentdelivering means to deliver the sound component to the speakerconcurrently with production of the raster, or to forbid delivery of thesound component to the speaker concurrently with and related to thedelivery of the raster, selectively.

2. In a radio transmitting and receiving system for the transmission andinterpretation of audio intelligence, the combination of a sendingstation including means to generate a carrier wave, means to modulatesaid carrier wave corresponding to the sound intelligence beingtransmitted; means to emit an interfering signal of audio frequency;together with means to receive and intelligibly translate said audiointelligence carrier wave signal and to produce an audio frequencyreplica of the audio intelligence corresponding to such carrier wavemodulated signal, said receiving and translating means including meansto receive and translate the audio frequency interfering signal and toinclude such audio frequency interfering signal translation in the audiofrequency replica of the audio frequency intelligence, means to producesound intelligence, sound delivery signal connections between the meanswhich receives and produces the audio frequency replica including theaudio frequency interfering signal translation, and `the soundintelligence producing means, for production of a sound replica of theintelligence, including Ithe interfering signal translation, means toproduce an inverted audio frequency signal corresponding to theinterfering signal translation, connections between the means whichreceives and produces the audio frequency replica of the audiointelligence including the interfering signal translation, and theinverter, and connections bctween the inverter and the sound deliveryconnections to the sound intelligence producing means, constituted toinclude the inverted interfering signal translation waves in the sounddelivery connections which are between the means which receives andproduces the audio frequency replica aforesaid, and the soundintelligence producing means, together with means to make effective orineffective said connections which are between the inverter and thesound delivery connections.

3. A radio receiver including means to receive a carrier frequency andproduce an audio translation thereof; said receiver also including meansto receive and translate an interfering signal to produce and deliver anaudio interfering signal; a speaker, connections from the audiointelligence translation producing means to the speaker, connectionsfrom the audio interfering signal producing means to the speaker;together with means in connection with the audio interfering signalproducing means constituted to produce and deliver an inversion of saidaudio interfering signal, and connections from the inversion producingmeans to the speaker constituted to deliver to the speaker an inversionof the audio interfering signal; and selector means constituted to makeoperative or inoperative the inversion producing means and theconnections from said inversion producing means to the speaker.

4. In a television system, the combination of a sending stationincluding means to emit video signals and means to emit audiointelligence signals, together with means to produce audio frequencyinterfering signals, and means to emit the audio frequency interferingsignals; and a receiver including means to receive and means totranslate said video signals to produce a raster, and including means toreceive and means to deliver the audio frequency intelligence signals,and means to receive and means to deliver the audio frequencyinterfering signals, all said means being constituted to produce anaudio signal delivery of the audio intelligence signals and to producesepa-rate audio frequency delivery of the interfering signals; an audiospeaker; and connections between the means which produces the audiointelligence signals delivery and the means which produces the separateaudio frequency interfering signals delivery, and the speaker; togetherwith an audio frequency interfering signal inverter constituted toreceive audio frequency interfering signals and deliver correspondinginverted audio frequency signals; a set of connections between the meanswhich delivers the separate audio frequency interfering signals, and theinverter, constituted to deliver the interfering signals to theinverter; a set of connections between the inverter and the deliveryconnections which are between the audio frequency intelligence signalsdelivery means, and the speaker; and switch means included in one ofsaid sets of inverter connections, said switch means having a firstdefined switch open position, and a second defined switch closedposition; together with operator controlled means constituted to movethe switch means to the second defined position.

5. In a radio system, the combination of a sending station includingmeans to emit audio intelligence signals,

together with means to produce audio frequency interfering signals, andmeans to emit the audio frequency intelligence signals and means to emitthe audio frequency interfering signals; and a receiver includingmeansto receive and means to translate the audio frequency intelligencesignals and means to receive and means to translate the audio frequencyinterfering signals, to produce an audio translation of the audiointelligence signals and an audio translation of the audio frequencyinterfering signals; and an audio speaker; and signal deliveryconnections between the means which produces the audio intelligencetranslations of the audio intelligence signals and the audiointerference signals, and the speaker; together with an audio frequencysignal inverter, a set of connections between the means which producesthe translation of the audio frequency interfering signals, and theinverter constituted to deliver the audio frequency interfering signalsto the inverter, another set of connections between the inverter and theaudio frequency signal delivery connections which are between the meanswhich produces the audio intelligence translations and the audiointerfering translations, to the speaker; and switch means included inone of said sets of connections, said switch means having a firstdefined switch open position, and a second defined switch closedposition; together with operator controlled means constituted to causethe switch means to be in its second dened closed position.

References Cited UNITED STATES PATENTS 1,941,067 12/1933 Armstrong325-64 XR 2,630,525 3/1953 Tomberlin et al. 325-64 XR 2,671,165 3/1954Gilpin et al. 325-64 XR JOHN W. CALDWELL, Acting Primary Examiner. DAVIDG. REDINBAUGH, Examiner. R. L. RICHARDSON, Assistant Examiner.

2. IN A RADIO TRANSMITTING AND RECEIVING SYSTEM FOR THE TRANSMISSION ANDINTERPRETATION OF AUDIO INTELLIGENCE, THE COMBINATION OF A SENDINGSTATION INCLUDING MEANS TO GENERATE A CARRIER WAVE, MEANS TO MODULATESAID CARRIER WAVE CORRESPONDING TO THE SOUND INTELLIGENCE BEINGTRANSMITTED; MEANS TO EMIT AN INTERFERING SIGNAL OF AUDIO FREQUENCY;TOGETHER WITH MEANS TO RECEIVE AND INTELLIGIBLY TRANSLATE SAID AUDIOINTELLIGENCE CARRIER WAVE SIGNAL AND TO PRODUCE AN AUDIO FREQUENCYREPLICA OF THE AUDIO INTELLIGENCE CORRESPONDING TO SUCH CARRIER WAVEMODULATED SIGNAL, SAID RECEIVING AND TRANSLATING MEANS INCLUDING MEANSTO RECEIVE AND TRANSLATE THE AUDIO FREQUENCY INTERFERING SIGNAL AND TOINCLUDE SUCH AUDIO FREQUENCY INTERFERING SIGNAL TRANSLATION IN THE AUDIOFREQUENCY REPLICA OF THE AUDIO FREQUENCY INTELLIGENCE, MEANS TO PRODUCESOUND INTELLIGENCE, SOUND DELIVERY SIGNAL CONNECTIONS BETWEEN THE MEANSWHICH RECEIVES AND PRODUCES THE AUDIO FREQUENCY REPLICA INCLUDING THEAUDIO FREQUENCY INTERFERING SIGNAL TRANSLATION, AND THE SOUNDINTELLIGENCE PRODUCING MEANS, FOR PRODUCTION OF A SOUND REPLICA OF THEINTELLIGENCE, INCLUDING THE INTERFERING SIGNAL TRANSLATION, MEANS TOPROFIT-01 DUCE AN INVERTED AUDIO FREQUENCY SIGNAL CORRESPONDING TO THEINTERFERING SIGNAL TRANSLATION, CONNECTIONS BETWEEN THE MEANS WHICHRECEIVES AND PRODUCES THE AUDIO FREQUENCY REPLICA OF THE AUDIOINTELLIGENCE INCLUDING THE INTERFERING SIGNAL TRANSLATION, AND THEINVERTER, AND CONNECTIONS BETWEEN THE INVERTER AND THE SOUND DELIVERYCONNECTIONS TO THE SOUND INTELLIGENCE PRODUCING MEANS, CONSTITUTED TOINCLUDE THE INVERTED INTERFERING SIGNAL TRANSLATION WAVES IN THE SOUNDDELIVERY CONNECTIONS WHICH ARE BETWEEN THE MEANS WHICH RECEIVES ANDPRODUCES THE AUDIO FREQUENCY REPLICA AFORESAID, AND THE SOUNDINTELLIGENCE PRODUCING MEANS, TOGETHER WITH MEANS TO MAKE EFFECTIVE ORINEFFECTIVE SAID CONNECTIONS WHICH ARE BETWEEN THE INVERTER AND THESOUND DELIVERY CONNECTIONS.